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Sidecar on an R90?

Hey all: Seeing as I can't seem to find a buyer for this lump, I have decided to convert it to a sidecar rig. (That's the original reason for selling the bike, we were going to buy an Ural). I have been told that I will need to replace the rear sub frame, with a unit designed for sidecar use, as well as add a fork brace and steering dampener. This is all before I buy the car. Anyone out there have an R90/sidecar rig who can give me some ideas? Thanks in advance. Vaya con Dios, Dutch

Lots of good info and examples on the advrider.com forum in the Hacks section.
You will be adding an additional subframe to the bike to stiffen the chassis and add support to the sidecar mounting, not replacing the rear subframe.

I have 2 Airhead sidecar rigs. You do need a subframe, but not to replace the bike's rear subframe. What you need is a sub frame that mounts to your bike main frame and the sidecar mounts to it. It distributes the sidecar loads better than just clamping a sidecar to the main frame. If you rig it up right, it'll be a better sidecar rig than a Ural (IMHO), you just won't have reverse gear, or the option of 2wd.
Here is a link to some pics of my R75/5 rig:

Hank and Bob; Thanks for the reply. Is the reinforcement kit available? I really wouldn't miss the reverse gear or the two wheel drive, they would just tempt me to get into situations that I couldn't get out of. ( I already have an R1100 for that!!) This is mainly going to get used to haul the wife around, as she suffers from an inner ear problem that makes it difficult to ride on a two wheeler.

A variety of sidecar dealers sell subframe kits for various bikes. One of them who has been doing this for a very long time is dauntless motors. Got to dmcsidecars dot com and give them the info on your R90, and what sort of sidecar you're looking at. They may even sell you a sidecar, too!

I have a 1983 R100 w/dauntless subframe/sputnic car.Steering was hard and wobbles Perry bushlong (texas)made new tripple trees to change trail,fixed steering.lacked power because of car,got different final drive 37:11 fixed that,need flat profile tires,mag wheels are best because of side load.Cost about 5K. Oh,well,what's money for anyway. Fun Ride!

The rigging is Dauntless (now DMC). The "sub-frame" is somewhat visible in the attached photo (it parallels the bike frame--it runs from above the cylinder and follows the frame down below the cylinder to the driver's footpeg area of the frame). Note also (second attached photo) the "loop" just forward of the passenger footpeg, it connects the back of the sidecar to both sides of the bike. The subframe is critical on post /2 BMW's as the "newer" frames can't carry the stresses of the sidecar.

I can take photos of all the rigging and sub-frame if you wish (as the attached photos don't show the parts very well).

This is my first sidecar so it "seems normal" to me. The photo may be a little deceiving as the space between bike and 'car looks larger than reality. That said, a large ammo box was bolted to the sidecar frame when I bought the rig (I've since remove the box).

You are the first to ask the question, now I'm curious. I would like the 'car tucked a little closer to the bike.

What is the track width (center of bike rear tire to center of hack tire) with your setup? I'm in the process of getting my piggybanks together so that I can join up my recently acquired sputnik car with my 1978 R100/7...

FWIW I have a similar rig, an '81 R100 with the same Velorex car but a year or two older; looks like the mounting setup and hardware are the same also except possibly for a different lower subframe rail. The toplinks and mouting look the same and the steering damper is the same but mounted a bit lower on the fork on yours.

My clearances are 3-1/2" from the bag to the rear body of the car, and 2-3/4" from the valve cover to the body of the car. It's a little too packed in (for the winter) among other bikes to easily measure the wheelbase at the moment but I might do that tomorrow. Based on the amount of thread left on the adjusting links, mine looks to be about as close as you could bring the two together and still have some play to adjust the toe-in/out. I didnt do the original setup but have pretty much overhauled it since I got it and it seems to be set up about right (but I'm not an expert!). I guess the real question is--how does yours ride with the car all the way out there?

SFaulkner, your track width does seem a bit wide. Thats not neccessarily bad and will help with stability in right hand curves. For comparison, My R75/5/Dnepr rig has a 46.5" track, and the valve cover is 3 1/2" off the sidecar body.

The chair will fly fairly easy in right handers, but I don't think its excessivly easy. My other rig, a R100RS with a larger Motorvation sidecar has a 60" track. The sidecar itself is heavier, and I find it hard to get the sidecar to lift.